@foxly, I get this error too.
happens in admin with the last alpha with WP 2.9.2 & last nights build with WP 3.0 when visiting wp-admin/admin.php?page=bp-album-embedded

also get
Warning: BP_Album_Admin::include_once( ... /html/wp-content/plugins/bp-album/includes/admin/admin-credits.php) [bp-album-admin.include-once]: failed to open stream: No such file or directory in ... /html/wp-content/plugins/bp-album/includes/sub-admin-core.php on line 162

Error #1: It happens because I’m using that screen to run test code right now. I think it also dumps your cache and I think it adds a bunch of extra image sizes. lol. Just delete all the BP Album+ DB tables, delete all your uploaded content, delete the cached image directories, deactivate, activate, and continue.

Here’s what I did to get error reported:
install wordpress3 with default settings, add buddypress plugin with default settings, set default buddypress theme and then the error pop up when activating BuddyPress Album+ plugin. I create new db and install same way with same error pop up inside dashboard when activating BuddyPress Album+. Hope it helps.

I went back to deactivate and then activate. It did NOT show the error. Only on new installs and no other plugins have problems so far. How it relate to web host or server confuse me. Didn’t try multisite yet. Thanks for your time.

I install on new database with new wordpress and buddypress install. Latest build only 1 error message (see below). Old build has 2 error after activate. Create new album and see blank album with question mark.

Warning: pathinfo() expects parameter 1 to be string, object given in /public_html/wp-content/plugins/bp-album/includes/album/sub-album-core.php on line 640